The present invention relates to a multi-directional bar code reading device for reading a bar code on an object that is to be read by projecting scanning beams from many directions.
A POS system (point-of-sales data management system) has been used in department stores and in supermarkets in order to enhance efficiency in the management of goods and in the check-out operation. It is desired that the goods and products labelled with bar codes be efficiently read out irrespective of the positions where they are placed.
In general, the problem of expediting material handling in a manner to minimize the need for human intervention still exists. Numerous systems have been developed to achieve this end. Some of these systems require a hand held reader for special labels which are placed on the articles. In other systems, great care must be taken to insure that the articles pass through a detection zone with their labels properly positioned and oriented with respect to a reader.
In data acquisition systems developed for retail point-of-sale applications, the typical way in which data entry is effected requires that a clerk read sales data from a ticket associated with each item of merchandise and then manually enter this data into the system using a keyboard. Therefore, a hand-held reader has been developed for scanning machine readable optical and magnetic codes applied to tickets pursuant to entering the sales data into the system. As is apparent, the automatic entry of sales data encoded in machine readable form can be effected more rapidly and accurately than manual entry via a keyboard.
The ultimate approach to the problem of data entry in this area appears to be the use of a fixed scanner for reading from a distance, machine readable, optically encoded data from a ticket attached to each item. This approach frees the clerk from the task of having to manipulate a reader and also considerably eases the problems of variations in scanning rate inherent in hand scanning.
According to a fixed type scanner that has heretofore been used in supermarkets and similar stores, the directions in which the scanning beams are projected are limited to just straight up from one surface or upward tilted directions. Therefore, an operator must carry out a cumbersome operation in which he makes sure the position or surface where the bar codes are attached to the goods, directs the device toward the reading direction and executes the reading operation. Moreover, even when the bar codes attached to the articles on a production line are to be automatically read out, the articles have to be so arranged in advance that the positions or surfaces where the bar codes are labelled are oriented in a predetermined direction, causing such problems as the facility of handling bulky objects and difficulty involved in arranging products having dissimilar sizes on the same line.
From the above discussion of a fixed type bar code reading device, it is necessary to provide an appropriate optical scanner device including the following:
1. A beam scanning unit; a plurality of reflecting mirrors arranged around the beam scanning unit; and a plurality of beam sources for emitting beams toward the beam scanning unit.
2. In item 1, the beams are controlled so as to be emitted from only one of the plurality of beam sources.
3. In the beam scanning unit of the item 1, both beam reflecting surfaces and beam non-reflecting surfaces are mounted on a scanning mirror to always emit only one scanning beam in the beam scanning unit.
With regard to the above item 3, a prior art U.S. Pat. No. 3,818,444 (Filed Jun. 29, 1972), was disclosed on Jun. 18, 1974, by Richard A. Connell (assignee: Pitney-Bowes, Inc.), entitled "Optical Bar Code Reading Method and Apparatus Having an X Scan Pattern".
4. In an optical scanning unit, a plurality of optical systems are exclusively controlled to always emit a scanning beam from only one optical system selectively.
This method includes: effecting scanning processes from a plurality of directions to select a beam from only one optical source by means of an operation of mirrors, selecting a beam mechanically by mirrors, and so forth.